Microdevices are sometimes implanted in a human or animal body to perform certain functions. One such microdevice is a microstimulator, which can be implanted in a body near a nerve or muscle motor point to stimulate certain regions of the body to help patients by, for example, moving a part of their body that may otherwise be disabled. Another example of such a microdevice is an implanted microsensor, which senses a body parameter and communicates wirelessly to an external controller. A further example of an implanted microdevice is a combination microstimulator and microsensor. It is often the case that after some period of time (e.g., weeks, months or years), the microdevice is desired to be removed from the body. In such a case, an operator (e.g., doctor, nurse, or technician) finds the specific location of the implant in the body and withdraws the implanted device, either for removal or replacement.
Dilators are used by surgeons during medical procedures to penetrate and dilate body tissue, such as during the implantation or removal (explantation) of medical devices, such as microdevices into or out of an animal or human body. As part of a procedure to remove an implanted microdevice, an elongate dilator can penetrate living tissue until its distal end reaches the microdevice, and then the hollow inner portion of the dilator can provide a lumen for the passage of other surgical tools or wires to expedite the removal of the microdevice. Some microdevices are equipped with an eyelet at the proximal end, which can then be connected to a wire or other device for the removal of the microdevice. There is a need for an improved type of dilator, which can make it easier to locate and remove an implanted microdevice.